Book distributor Advanced Marketing Services has served notice that its delay in releasing its 10-Q (quarterly report, see 'AMS Delays 10-Q') has put it in default of its lending covenants.  The lenders have given the company a waiver until September 30th, but AMS warned in its regulatory filing that there is no guarantee that it will be able to file its 10-Q by September 30th, or that the waiver will not be pulled.  The delay in filing the quarterly report is due to the federal investigation into advertising practices at the company.